Important Polyatomic Ions, Acids, Bases & Solubility Rules

67 vocabulary flashcards covering the major polyatomic ions, strong and weak acids/bases, net-ionic reaction guideline, and the six key solubility rules presented in the lecture notes.

Ammonium ion

NH4⁺ (charge +1)

Acetate ion

C2H3O2⁻ (charge −1)

Carbonate ion

CO3²⁻ (charge −2)

Benzoate ion

C7H5O2⁻ (charge −1)

Chromate ion

CrO4²⁻ (charge −2)

Bicarbonate ion (Hydrogen carbonate)

HCO3⁻ (charge −1)

Dichromate ion

Cr2O7²⁻ (charge −2)

Bisulfate ion (Hydrogen sulfate)

HSO4⁻ (charge −1)

Disulfate ion

S2O7²⁻ (charge −2)

Bisulfite ion (Hydrogen sulfite)

HSO3⁻ (charge −1)

Hydrogen phosphate (Dibasic phosphate)

HPO4²⁻ (charge −2)

Bromate ion

BrO3⁻ (charge −1)

Oxalate ion

C2O4²⁻ (charge −2)

Bromite ion

BrO2⁻ (charge −1)

Persulfate ion

SO5²⁻ (charge −2)

Chlorate ion

ClO3⁻ (charge −1)

Sulfate ion

SO4²⁻ (charge −2)

Chlorite ion

ClO2⁻ (charge −1)

Sulfite ion

SO3²⁻ (charge −2)

Cyanate ion

OCN⁻ (charge −1)

Tartrate ion

C4H4O6²⁻ (charge −2)

Cyanide ion

CN⁻ (charge −1)

Tetraborate ion

B4O7²⁻ (charge −2)

Dihydrogen phosphate ion

H2PO4⁻ (charge −1)

Thiosulfate ion

S2O3²⁻ (charge −2)

Hydroxide ion

OH⁻ (charge −1)

Hypochlorite ion

ClO⁻ (charge −1)

Iodate ion

IO3⁻ (charge −1)

Nitrate ion

NO3⁻ (charge −1)

Nitrite ion

NO2⁻ (charge −1)

Perchlorate ion

ClO4⁻ (charge −1)

Permanganate ion

MnO4⁻ (charge −1)

Thiocyanate ion

SCN⁻ (charge −1)

Arsenate ion

AsO4³⁻ (charge −3)

Arsenite ion

AsO3³⁻ (charge −3)

Borate ion

BO3³⁻ (charge −3)

Citrate ion

C6H5O7³⁻ (charge −3)

Phosphate ion

PO4³⁻ (charge −3)

Phosphite ion

PO3³⁻ (charge −3)

Nitric acid (strong)

HNO3 – one of the seven strong acids

Sulfuric acid (strong)

H2SO4 – strong acid (diprotic)

Perchloric acid (strong)

HClO4 – strong acid

Chloric acid (strong)

HClO3 – strong acid

Hydrochloric acid (strong)

HCl – strong acid

Hydrobromic acid (strong)

HBr – strong acid

Hydroiodic acid (strong)

HI – strong acid

Carbonic acid (weak)

H2CO3 – common weak acid

Phosphoric acid (weak)

H3PO4 – common weak acid

Acetic acid (weak)

HC2H3O2 – weak acid found in vinegar

Hydrofluoric acid (weak)

HF – weak acid despite being binary

Sodium hydroxide (strong base)

NaOH – alkali metal hydroxide

Lithium hydroxide (strong base)

LiOH – alkali metal hydroxide

Potassium hydroxide (strong base)

KOH – alkali metal hydroxide

Rubidium hydroxide (strong base)

RbOH – alkali metal hydroxide

Magnesium hydroxide (strong base)

Mg(OH)2 – strong base, slightly soluble

Calcium hydroxide (strong base)

Ca(OH)2 – strong base, slightly soluble

Strontium hydroxide (strong base)

Sr(OH)2 – strong base

Barium hydroxide (strong base)

Ba(OH)2 – strong base

Beryllium hydroxide (weak base)

Be(OH)2 – weak base

Ammonia (weak base)

NH3 (or NH4OH in solution) – classic weak base

Net Ionic Reaction Rule

Split strong acids, strong bases, and aqueous salts; keep liquids, solids, gases, and all weak acids/bases together.

Solubility Rule 1

All alkali-metal and ammonium (NH4⁺) compounds are soluble.

Solubility Rule 2

All acetate, perchlorate, chlorate, and nitrate compounds are soluble.

Solubility Rule 3

Silver, lead, and mercury(I) compounds are insoluble.

Solubility Rule 4

Chlorides, bromides, and iodides are soluble (except when paired with Ag⁺, Pb²⁺, or Hg2²⁺).

Solubility Rule 5

Carbonates, hydroxides, oxides, phosphates, silicates, and sulfides are insoluble.

Solubility Rule 6

Sulfates are soluble except for calcium and barium (CaSO4 and BaSO4 are insoluble).